Manufacture of halogenated hydroquinone



June 6,1933. H. voN BRAMER ET AL MANUFACTURE OF HALOGENATED HYDROQUINONE Filed July 13 All @ESS NY Y t mit@ wmvm.

AI mzgrO Harold Inl'mzez;

June 6, 1933. H. voN BRAMER ET AL MANUFACTURE OF HALOGENATED HYDROQUINONE Filed July 15, 1932 2' Sheets-Sme?l Jdmwzabr' a Harold Bll/Blumen Patented June 6, 1933 l UNITED STATES YONu BEAMER AND JOI-IN" W. ZABRISKIE, OF K'INGSPORT, TENNESSEE, ASSIGN- 1 ORS T0 EASTMAN KODAK COMPANY, 0F ROCHESTER,UNEW YORCIL'A CORPORATION on NEW YORK i PATENT* OFFICE iimmrmtc'ru1an` or HALOGENATED HYDROQUINONE wappiicatjon. ined my 13,

This invention relates tothe manufacture of halogenatcd hydroquinones. y `One object of the invention is to provideaprocess for making chlorinated hydroquinone bythe direct chlorination of hydroquinone. Another object is to providea process for making pure monohalogenated hydroquinones by the directhalogenation of hydroquinonc.

lilonochlorohydroquinone and monobromohydroquinone are useful, amongother things, as photographic developers. Monochlorohy-V droquinone has usually been prepared by the simultaneous chlorination and reduction of quinone by treatingquinone With concentratedhydrochloric acid, or by passing dry hydrogen chloride into a benzene solution of quinone. 1 However, quinone is unpleasant and difficult to Work vvith,`on account of its extremely pungent odor andits tendency t0.

i0V become converted into tarry bodies. When attempts Were, made .to chlorinate hydroquinone udirectly 1n solution or suspension 1n Water, methanol, benzene, toluene, chloroform,

. dichlorethane, etc., some of the hydroquinone vvasV oxidized to quinone or quinhydrone, re-

sulting in dark colored products containing much tarry matter. f

We have discovered that when hydroquinone, is suspendedin carbon tetrachloride, it may be chlorinated or-brominated directly, Without oxidation, by passing chlorine or bro mine into the suspension, andfurthermore, that if the monohalogenatedl hydroquinone` formed is removed continuously from the reaction mixture, the formationof more highly halogenated products is avoided. f Unless the monohalogenated hydroquinone is 1 removed as formedit isextremely diiicultto halogenate all of the hydroquinonepwithout the formation of some 'dihalogenated hydroquinone. "y .1 1 In making monochlorohydroquincne, if the presence `of; dichlorohydroquinone in the .D product. is notobjectionable, the `operation may be carried out in an apparatus, the laboratoryforrn of which 1s represented 1n Figure 1. Theffollowingis .an example of the procedure `which may be followedfwith the apparatus depicted in Fig. 1. Y y.

hundred and ten grams of hydrocluin-` 1932. Serin No. 622,276.

one is ground to a` fine powder,` and suspendedm about 1500 cc.` of carbon tetrachloride 1n a -liter liaskl provided with an agitator 2" and inlet and outlettubes 3 and f1. A weighed cylinder of chlorine is connected to the inlet tube -3 through a safety bottle 5. The outlet `tube 4 is connected to `an absorption bottle 6 for taking up the hydrogen chlo ride evolved in the reaction. Provisionis made for cooling the flask with Water, and for Weighing the! chlorine cylinder and the absorption bottle.` Over a period of three hours, 71 grams of chlorine is passed into the hydroquinone suspension, With constant agi-` tation. The chlorination is then discontinued." The carbon tetrachloride is evaporated in vacuo'and the residue carefully dried, the residue consisting of monochlorohydroquinone together vvithsome dichlorohydroquinone. 1 1

Whenit is desired to obtain puremonochlorohydroquinone, Vfree from more highly chlorinated products, the process may be carried out in an `apparatus such as is illustrated diagrammatically` in vFigure 2, by a continuous process of Which the following is illustrative.- n f y Referring to Figure 2,1one liter offcarbon tetrachloride is placedin the still 11 and evaporation started and continued at a rate of about 70 cc. per minute, the condensed carbon `tetrachloride eventually returning to thestilllthrough line 19for re-evaporation, Thestill may be heated by any `suitable means, suchasajgasiiame, liquid bathor steam. The vaporisled up throughthe steam jacketed tube 12 and then to brine cooled condensers 13 Where it is condensed and the temperature of the condensate lowered to about OO C. From the condensers 13 the cold carhontetrachloride passes to the topV of the are provided with calcium chloride tubes or thelike to prevent condensation of the moisture `from theairin the carbon tetrachloride. Drains 20 may be providedl as indicated.

From the absorption column 14, the solution of chlorine in carbon tetrachloride is fed into the chlorinator 16, which is provided with an agitator 17 and a suitable filter 18 containing a filtering medium which is not attacked by thel elements treated, such, for instance, as asbestos. At the start of a run, 110 grams of hydroquinone suspended in about two liters of carbon tetrachloride are placed in the chlorinator 16 and agitated; the hydroquinone is insoluble in carbon tetrachloride. The hydroquinone, upon coming in contact with the carbon tetrachloridechlorine solution fed into the chlorinator, rapidly takes up the Ychlorine therefrom, forming monochlorohydroquinone which is soluble in carbon.y tetrachloride; the solution of monochlorohydroquinone thus formed passes through the filter 18and back to the still 11 by means of the line 19. The head required to filter the solution is regu-lated by means of the vlevel control in the line 19. The level of the liquid in the chlorine absorption column is regulated by goose necks at the proper level upon each side thereof. When about one-half Vof the hydroquinone has been chlorinated, and thev chlorinated hydroquinone concentrated inthe still 11 by the return of the carbon tetrachloride solution of chlorinated hy'droquinone and re- `evaporation Vof the carbon tetrachloride in a continuous manner, the operation may be stopped and the hot concentrated solution of monochlorohydroquinone` in the still 11 allowed to cool. The crystals which separate out are separated from the mother liquor and dried, the mother liquor beingv returned to the still 11 to join with further processing. If desired, provision may be made for feeding in hydroquinone and chlorine vwithout interruption and continuously withdrawing the concentrated solution of monochlorohydroquilnone without stopping the process, although the' latter is a simple and quick step which hardly makes the process discontinuous.

It will be understood that the above eX- amples and the apparatus shown areV merely illustrative of two forms of carrying out our invention, and that we are not limited by them. The quantities mentioned'V may, of course, be varied considerably. ForV instance, the amount .of chlorine absorbed in the carbon tetrachloride or the ratio of this solution to hydroquinone affect the efficiency of the process only and not'thel fact thatV it works. While we prefer to carry on the chlorination at temperatures ra-nging from 0O C. to 25 C., approximately, we may luse any temperature from about minus 5 C. up almost to the boiling point of carbon tetra-L chloride without danger Yof ehlorinating the hydroquinone beyond the monochloro stage, provide the chlorohydroqui-none is removed.

z from the reaction mix-ture substantially as .fast as it is formed. Formation of the monochlorohydroquinone is favored by rapid agitation, anhydrous condition of the reaction materials, and a line state of suspension of the hydroquinone. The apparatus may, of course, be varied to suitthe conditions and scale of operation.

A flow sheet representing a method for carrying out the operation on a commercial scale is given inFig. 3. From this will be observed the preferred form of carrying out the invention, namely, as a completely continuous process. The various pieces of apparatus represented by this flow sheet are, of course, well known to those skilled in the chemical arts and need not be further described. From this flow sheet it will be ob-l served that the carbon tetrachloride continuously flows into thev chlorine absorption column and after chlorination flows therefrom into the' chlorinator. From the latter, the monochlorohydroquinone solution passes back to the still from whence a proportion of the concentrated solution is continuously withdrawn to storage and evaporators for removal of carbon tetrachloride and drying of the monochlorohydroquinone.

ldlhile we have described in detail the method of vmaking monochlorohydroquinone, we have found that monobromohydroquinone maybe made in the same manner, under the same conditions, bromine being used in place of chlorine. Where weights of halogen are referred to, approximately 160 g. of bromine is used in chlorine.

Vhat we claim as our invention and desire to be secured by Letters Patent of the United States is:

1. A process of making chlorinated hydroquinone, which comprises treating hydroquinone submerged in carbon tetrachloride with chlorine.

2. A process of making monochlorohydroquinone, comprising suspending hydroquinone in carbon tetrachloride and treating it with chlorine.v

3. A process of'makingmonohalogenated hydroquinone, comprising suspending hydroquinone in carbon tetrachloride, treating it with a haolgen selected from the group consisting of chlorine and bromine, and contiuuously removing the monohalogenated hydroquinone from the .reaction mixture.

4. A process of making monochlorohydroquinone, comprising suspending hydroquinone in carbon tetrachloride, treating it with chlorine, and continuously removing the monochlorohydroquinone from the reaction mixture. A

5. A process of making monobromohydroquinone, fcomprising suspending hydroquinone `in carbon tetrachloride, treating it with bromine, and continuously removing the place of approximately 71 g. of

monobromohydroquinone from the reaction mixture. y

6. A process of chlorinating hydroquinone which comprises treating hydroquin'one with carbon tetrachloride containing dissolved chlorine.

7 A process of halogenating hydroquinone which comprises treating hydroquinone with carbon tetrachloride containing a dissolved halogen selected from the group consisting of chlorine and halogenated hydroquinone from the hydroquinone substantially as fast as formed.

8. A process of chlorinating hydroquinone Whichcomprises treating hydroquinone With carbon tetrachloride containing dissolved chlorine and removing the chlorinated hydroquinone from the hydroquinone substantially as fast as formed.

9. A process of brominating hydroquinone which comprises treating hydroquinone with carbon tetrachloride containing dissolved brolnine and removing' the broininated hydroquinone from the hydroquinone sulostan-` tially as fast as formed. a 10. A continuous process of making monochlorohydroquinone which tilling carbon tetrachloride from a still, passing it through a chlorinator to Which chlorine is admitted, passing the carbon tetrachloride containing chlorine into a mixer containing hydroquinone suspended in carbon tetrachloride, returning the carbon tetrachloride containing dissolved monochlorohydroquinone to the still, and redistilling the carbon tetrachloride.

Signed at Kingsport, Tennessee, this 5th day of July, 1932.

HAROLD VON BEAMER. JOHN W. ZABRISKIE.

bromine and removing the comprises disv 

